Generation and validation of a floxed FosB mouse line

Expression of the FosB gene has been studied extensively in many fields using a variety of tools. However, previous techniques have had a variety of caveats, from potential off-target effects (e.g., overexpression of FosB, ΔFosB, or a dominant negative mutant of JunD, termed ΔJunD) or confounding developmental effects (e.g., the constitutive FosB knockout mouse). Therefore, we sought to create a floxed FosB mouse line that will allow true silencing of the FosB gene with both spatial and temporal control. Here, we detail the cloning strategy, production, and validation of the floxed FosB mouse. We demonstrate methodology for breeding and genotyping, and show that viral-mediated expression of Cre recombinase in a targeted, discrete brain region ablates expression of the FosB gene in floxed but not wild type mice. Thus, the floxed FosB mouse presented here represents an important new tool for the continued investigation of this critical gene.